Premises, Furniture, and Equipment (Detail) - Premises, Furniture, and Equipment - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Land	$ 43,442	$ 51,104
Premises	152,444	148,963
Furniture and equipment	90,672	85,489
Total cost	286,558	285,556
Accumulated depreciation	(171,708)	(156,473)
Net book value of premises, furniture, and equipment	114,850	129,083
Assets held-for-sale	7,428	2,026
Total premises, furniture, and equipment	$ 122,278	$ 131,109